Joe Celko's SQL for Smarties, 3rd Edition

25.2. Arrays via Subscript Columns

Another approach to faking a multidimensional array is to map arrays into a table with an integer column for each subscript, thus:

CREATE TABLE Foobar
(i INTEGER NOT NULL PRIMARY KEY
   CONSTRAINT valid_array_index
   CHECK(i BETWEEN 1 AND 5),
 element REAL NOT NULL);

This looks more complex than the first approach, but it is closer to what the original Pascal declaration was doing behind the scenes. Subscripts resolve to unique physical addresses, so it is not possible to have two values for foobar[i]; hence, i is a key. The Pascal compiler will check to see that the subscripts are within the declared range; hence the CHECK() clause.

The first advantage of this approach is that multidimensional arrays are easily ...